The present invention, in some embodiments thereof, relates to a semiconductor chemical sensor and, more particularly, but not exclusively, to a gas sensor based on a field effect transistor.
Commercially available gas sensors include IR sensors, Toxic sensors, and Pellistors, all sold by City Technology, Ltd., and metal oxide gas detectors, sold by Figaro USA, Inc. (FIS, Inc.). The sensors sold by City Technology are described, for example, at worldwidewebdotcitytechdotcom, and the sensors sold by Figaro are described, for example, at worldwidewebdotfigarosensordotcom. Gas sensors that could be manufactured more cheaply, and/or have greater sensitivity and/or greater specificity, would be useful.
Gas sensors based on nanowire of various materials, for example Si, ZnO, SnO, and other materials, can exhibit exceptionally high resolution and sensitivity. However, the manufacture of commercial gas sensors based on such nanowires may not be feasible at the present time, since the fabrication of these structures, for example with the VLS method, cannot accommodate high volume manufacturing (HVM). Alternatively, high volume CMOS manufacturing of nanowires could be realized in the future but with a substantial increase in cost, even several orders of magnitude.
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